<template>
  <view class="u-line-progress" :style="[$u.addStyle(customStyle)]">
    <view ref="u-line-progress__background" class="u-line-progress__background" :style="[{
        backgroundColor: inactiveColor,
        height: $u.addUnit(height),
      }]" />
    <view class="u-line-progress__line" :style="[progressStyle]">
      <slot>
        <text v-if="showText && percentage >= 10" class="u-line-progress__text">{{ innserPercentage + '%' }}</text>
      </slot>
    </view>
  </view>
</template>

<script>
import props from './props.js'
// #ifdef APP-NVUE
const dom = uni.requireNativePlugin('dom')
// #endif
/**
   * lineProgress 线型进度条
   * @description 展示操作或任务的当前进度，比如上传文件，是一个线形的进度条。
   * @tutorial https://www.uviewui.com/components/lineProgress.html
   * @property {String}			activeColor		激活部分的颜色 ( 默认 '#19be6b' )
   * @property {String}			inactiveColor	背景色 ( 默认 '#ececec' )
   * @property {String | Number}	percentage		进度百分比，数值 ( 默认 0 )
   * @property {Boolean}			showText		是否在进度条内部显示百分比的值 ( 默认 true )
   * @property {String | Number}	height			进度条的高度，单位px ( 默认 12 )
   *
   * @example <u-line-progress :percent="70" :show-percent="true"></u-line-progress>
   */
export default {
  name: 'ULineProgress',
  mixins: [uni.$u.mpMixin, uni.$u.mixin, props],
  data() {
    return {
      lineWidth: 0
    }
  },
  computed: {
    progressStyle() {
      const style = {}
      style.width = this.lineWidth
      style.backgroundColor = this.activeColor
      style.height = uni.$u.addUnit(this.height)
      return style
    },
    innserPercentage() {
      // 控制范围在0-100之间
      return uni.$u.range(0, 100, this.percentage)
    }
  },
  watch: {
    percentage(n) {
      this.resizeProgressWidth()
    }
  },
  mounted() {
    this.init()
  },
  methods: {
    init() {
      uni.$u.sleep(20).then(() => {
        this.resizeProgressWidth()
      })
    },
    getProgressWidth() {
      // #ifndef APP-NVUE
      return this.$uGetRect('.u-line-progress__background')
      // #endif

      // #ifdef APP-NVUE
      // 返回一个promise
      return new Promise(resolve => {
        dom.getComponentRect(this.$refs['u-line-progress__background'], (res) => {
          resolve(res.size)
        })
      })
      // #endif
    },
    resizeProgressWidth() {
      this.getProgressWidth().then(size => {
        const {
          width
        } = size
        // 通过设置的percentage值，计算其所占总长度的百分比
        this.lineWidth = width * this.innserPercentage / 100 + 'px'
      })
    }
  }
}
</script>

<style lang="scss" scoped>
@import '../../libs/css/components.scss';

.u-line-progress {
  align-items: stretch;
  position: relative;
  @include flex(row);
  flex: 1;
  overflow: hidden;
  border-radius: 100px;

  &__background {
    background-color: #ececec;
    border-radius: 100px;
    flex: 1;
  }

  &__line {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    align-items: center;
    @include flex(row);
    color: #ffffff;
    border-radius: 100px;
    transition: width 0.5s ease;
    justify-content: flex-end;
  }

  &__text {
    font-size: 10px;
    align-items: center;
    text-align: right;
    color: #ffffff;
    margin-right: 5px;
    transform: scale(0.9);
  }
}
</style>
